离子束溅射制备与改性增强Zn4Sb3薄膜热电特性及相关物理机制研究

Thermoelectric material is a kind of new energy material which has the functional characteristic of conversion between thermal energy and electrical energy. But they are relegated to niche applications due to the poor energy conversion efficiency. Zn4Sb3 is one of the promising thermoelectric materials and low dimensional thin film technique can improve its thermoelectric properties. Based on the analysis of the key scientific problems for preparing high-performance Zn4Sb3 thin films, the ion beam sputtering and modification technique will be used to prepare the Zn4Sb3 thin films in order to enhance the its thermal transport properties. At first, the influence of ion beam sputtering parameter on the crystal structure and composition of Zn4Sb3 thin films will be investigated and the physical mechanism will be gained. Then, the other ion beam will be used for modified the micro-structure of the Zn4Sb3 thin films. The effects of ion beam parameter on the atomic motion and crystal nucleation will be studied. The micro-structure and thermoelectric properties will be measured. The physical mechanism of the matter interaction mechanism and the relationship between micro-structure and thermoelectric properties will be obtained based on the theoretical and experiment studies. As the final goal, high performance Zn4Sb3 thin films will be gained by suing ion beam sputtering and modified technology after the theoretical and experiment studies.

热电材料可以实现热能和电能的直接相互转换，是极具竞争力的新能源材料，但低的热电转换效率制约了其广泛的应用。Zn4Sb3是具有前景的热电材料之一，低维薄膜化是提高其热电性能的有效方法。本项目在综合分析高质量Zn4Sb3薄膜生长存在的关键科学问题的基础上，提出采用离子束溅射制备Zn4Sb3薄膜，并配合离子束改性技术调控薄膜微结构，以增强其热电输运特性。首先，研究离子束溅射参量对Zn4Sb3薄膜晶体结构、化学成分的影响，建立相关性物理模型；随后，采用离子束辅助溅射和表面后处理技术，对薄膜进行微结构改性，深入研究改性参量对薄膜原子移动、晶核形成等微结构的影响，并分析薄膜热电输运特性的变化规律，以此建立离子束与物质相互作用机制及薄膜微结构与热电输运特性之间的相关性物理机理；进而，通过离子束溅射和改性参量的调节，调控出能够有效增强薄膜热电输运特性的微结构，实现Zn4Sb3薄膜热电性能的大幅度提高。

高性能薄膜热电材料及器件的研发，是目前热电材料研究领域的前沿课题。Zn4Sb3基热电材料是极具应用前景的热电材料体系，深入研究其薄膜材料的制备工艺，是进一步提高其热电性能及降低制造成本的关键所在。鉴于此，本项目采用离子束溅射方法，结合离子束改性技术调控Zn4Sb3基薄膜微结构，通过深入探索离子束溅射（改性）参量与薄膜微结构及热电输运特性之间的关联特性，掌握了基于离子束溅射结合离子束后处理技术制备Zn4Sb3基薄膜的生长机理和关键技术；进而通过工艺参量的优化调节，最终实现了热电优值接近1.2的Zn4Sb3基热电薄膜的制备；同时在本项目的支持下，也相继开发了磁控溅射技术制备Zn4Sb3基热电薄膜及有机-无机复合热电薄膜的制备新技术。目前相关研究成果已经发表在国内外著名学术期刊上，并获得了国家发明专利授权，为热电薄膜材料的创新性技术研发提供科学依据和理论支持。